What's causing the smoky haze

Jul 10 2012

The smoky haze drifting over much of B.C., blurring the sun, is coming from fires in Siberia, central Russia and, possibly, from other fire-stricken areas in eastern Asia, weather and air quality specialists say.

“The smoke and dust travels across the Pacific Ocean in an upper-level flow pattern and it’s just the right trajectory to produce some issues in blocking the sun.”

The haziness started during the weekend and probably will continue until a cold front comes in or the fires are brought under control, said Eric Taylor, provincial air-quality meteorologist.

“It appears to be coming from eastern Asia fires, not only in Siberia, but also in central Russia, China and even Vietnam,” he said.

“It has taken six or seven days to get across the Pacific. … It is getting caught up in high-level winds moving across the Pacific at about 8,000 metres.”

The smoke is travelling about 10,000 kilometres.

The B.C. Interior is seeing higher concentrations of smoke than Vancouver Island. Air-quality advisories have been issued in communities such as Williams Lake, Quesnel, Prince George and Smithers, Taylor said.

Anyone with underlying health problems should postpone strenuous exercise outside in areas where there is such an advisory, he said.

On the positive side, the automatic sun filter keeps temperatures slightly lower than if there were a clear sky. The haze is also leading to spectacular sunsets, with the sun disappearing beneath the horizon as a bright red ball.

“A lot of the small particles are brown so they give that reddish-brown hue, and the sunset already has that reddy-orange glow,” Taylor said.

There is no estimate on when the Siberian fires will be brought under control. Metereologists said the earliest a cold front could be expected is late this week.